Coated article



Oct. 23, 1945. T. K. cox 2,387,498

COATED ARTICLES Filed Dec. 6, 1941 LUBP/CA /v r (A N T/ OXIDANT) NSUL A HON INVENTOP T. K. C0 BY ATTOR Y oi the insulation by the the surface of a wire Patented Oct. 23., 1945 COATED ARTICLE Thomas K.

Randallstown,

Mi, minor to Western Electric Company, Incorporated, New

York, N. Y., a

corporation of New York Application December 6, 1941, Serial No. 421,911 14 Claims. (Cl. 174-120) This invention relates to the treatment of metallic articles and more particularly to the treatment of wire prior to its being covered with insulation.

In the manufacture of rubber insulated wire it has been the practice to coat the wire with a lubricant prior to its entrance into the extruding machine which applies the insulation; This practice was made necessary because the metal scraped oi oi the lubricant-free wire when it passed through the core tube of the extruding machine soon jammed the tube, causing the wire to break. Mineral oil, or a similar lubricant has heretofore been used successfully to prevent the jamming of the core tube. The mineral oil served the double purpose oi facilitating the passage of the wire through the core tube and preventing the adherence of the insulation to the wire. Wire having a non-adherent insulat ing coating is particularly desirable where a number of electrical connections are to be made rapidly, because the insulation may be readily removed from the wire to provide clean, bare wire for the connections. However, for certain purposes, even a small amount of contamination mineral oil makes its use prohibitive.

Objects of this invention are to provide improved methods of treating metallic surfaces and'to provide improved treated metallic articles...

These and other objects are accomplished by the improved methods and articles comprising this invention as disclosed in the annexed drawing and as hereinafter described.

In general, the invention comprises treating a metallic article with an antioxidant for rubher and covering the treated article with a sheath of vulcanizable material.

The accompanying drawing illustrates'a wire produced according to applicants invention. In the drawing the single figure shows a perspective view of a coated wire with sections of the coatings removed to more clearly disclose the invention.

In accordance of the invention,

with one specific embodiment the metallic surface treated is l0, which may be of any metal composition, although in the prefered embodiment of the invention it consists of copper or a copper alloy. A coating consisting of an antioxidant for rubber is designated by the nu-' meral H, which coating in actual practice is quite thin. Therefore, the coating l l shown in the drawing is purely a schematic presentation A covering of vulcanized insulating material I2 is applied over the coating H by any suitable process, but is preferably extruded thereover by means of an extrusion press common to this art and then vulcanized in a continuous vulcanization chamber of known construction. The insulating material i2 is preferably a vulcanized rubber composition, although any other suitable vulcanizable material may be used.

In the manufacture of an insulated wire of the type disclosed, the bare wire is run through an extrusion press of known design and just prior to its entrance into the'extrusion press the wire is coated with a thin film of an antioxidant for rubber in a liquid state. The term liquid state, as used herein and in the annexed claims, means a state in which the antioxidant has the flowing properties of a liquid, whether the material is naturally liquid at room temperatures, is molten because heated, or is dissolved in a suitable solvent.

The antioxidant acts as a lubricant to facili tate the passage of the wire through the core tube of the extrusion press and prevents breakage of the wire due to clogging of the core tube by metal particles scraped from the wire. In the extrusion press a covering of vulcanizable insulating material, such as a rubber compound, is applied over the coated wire. The thus covered wire is then advanced through a continuous vulcanization chamber of suitable design, wherein the insulating material is vulcanized upon the wire.

When extruded over the antioxidant coating described above and vulcanized in situ, such a covering may be readily and cleanly removed from the wire iii. The desirability of an easily removable insulating covering in making electrical connections is at once apparent to those skilled in the art.

A number of rubber antioxidants have been tested to determine their suitability for the purpose of this invention and all have been found to be successful. Among the most suitable oi the antioxidants tried were those which are liquid at ordinary temperature. The liquid antioxidants sold under the trade names Antoxf (a butyraldehyde-aniline condensation product sold by the E. I. du Pont de Nemours and Company) and B. L. E. (a diphenylamine acetone reaction product sold by the Naugatuck Chemical Company) have proven to be especially suitable for use in practicing the invention. Both 01' these compounds are liquid at ordin temperatures and. lubricate the passage or the wire through the, extrusion press and prevent adherence of the vulcanized insulation covering to the wire.

Antioxidants for rubber which melt at slightly; above room temperature may the liquid antioxidants with substantially equal success by beating them above their melting mints beforeapplrins them to a wire. For example, the material known as "Neozone A (phenyl-alpha-napthylamine sold by the E. I. du Pont de Nemours and Company), which melts at a point between 55 and 60" C., was melted and applied to a wire, and the coated wire covered with an extruded rubber covering in the usual manner. This melted antiomdant proved to be a good lubricant and eiiectively prevented the ad'- herence or the insulation to the wire.

However, this invention is not confined to the use of liquid antioxidants, that is, those anti.- oxidants which are liquid at room temperature, or to antioxidants whose melting points are low enough that they may be applied to the object to be covered in a molten state. Antioxidants for rubber which are solid at temperatures considerably above room temperature may be used with satisfactory results if dissolved in some suitable solvent and applied to the object to be coated. For example, the material known as Akroflex C" (sold by the E. I. du Pont de Nemours and Company), consisting of about 35% diphenyl para-phenylene and about 65% phenyl-alpha-- napthylamine and having a melting point between 60 and 80 C., was dissolved in acetone and applied in the same manner as the other antiomdants. The wire thus coated was sufilciently lubricated to pass through the coretube of an extrusion press without scraping oil metal and the final vulcanized coating did not adheresto the wire.

In view of the above-outlined results, it is apparent that the use of an antioxidant as a conductor lubricant is dependent only upon its being applied to the conductor in a liquid state, no matter whether such liquid state is the normal state at room temperatures, is promoted by external heat, or is obtained by dissolving the antioxidant in some suitable solvent.

While all of the rubber antioxidants in the liquid state are satisfactory lubricants, such antioxidants dissolved insolvents will not necessarily be eiiective to prevent adherence of the vulcanized covering to the metal article covered because the solvents employedmay affect the result. The

adherence of the covering to the article covered may be controlled by the characterof the 'solution of the antioxidant employed to coat the article. Adhesion-preventive solvents such as mineral oils, etc., and adhesion-promoting solvents or plasticizers such as tricresyl phosphate, dibutyl phthalate, amyl acetate, higher fatty acids, etc., may be used separately or in conjunction with one another in order to obtain the degree of ad'- hesion desired. Generally, however, the liquid antioxidants and melted antioxidants, without the addition of any other ingredient, do prevent adhesion.

Although in the specific embodiment of the invention shown in the attached drawing a solid wire is employed, itis to be understood that the invention is applicable to the treatment of both solid andstranded wires. Also, while the invention has been described as applied to the treatment of wires, it is obvious that the invention be used in place (i enemas may be employed with satisfactory results in the treatment or strip or sheet material and of elongated articles of various cross sections. The invention is not limited to the treatment of continuous lengths of materials, but is applicable whenever it is desirable either to control the adhesion of a vulcanized covering to a metallic suriace and/or where it is desired to lubricate an article before it is covered with a vulcanizable material.

What is claimed is:

1. The process treating a metallic article. which comprises coating the article with a rubber antioxidant selected from the group consistnot, diphenylamine acetone reaction product, phenyl-alpha-napthylamine and a mixture 0! about 35% diphenyl-para-phenylene with about 65% henyl-alpha-napthylamine, applying there- 2 over a covering of vulcanizable rubber insulating compound, and vulcanizing the vulcanizable compound.

2. The process of treating a filamentary me tallic conductor, which comprises coating the conductor with a rubber antioxidant selected from the group consisting'of butyraldehyde-aniline condensation product, diphenylamineacetone reaction product, phenyl-alpha-napthylamine and a mixture of about 35% diphenyl- 3o para-phenylene with about 65% phenyl-alphanapthylamme, extruding thereover a covering of a vulcanizable rubber insulating compound, and vulcanizing the vulcanizable compound.

3. The process of treating a filamentary metallic conductor, which comprises coating the conductor with a-rubber antioxidant consisting of a butyraldehyde-aniline condensation product, extruding thereover a covering of a vulcanizable rubber insulating'compound, and vulcanizing the vulcanizable compound.

4. The process of treating a filamentary metallic conductor, which comprises coating the conductor with a rubber antioxidant consisting of 'phenyl-alpha-napthy-lamine, extruding thereover a covering of a vulcanizable rubber insulating compound, and vulcanizing the vulcanizable compound. a

5. The process of treating a filamentary metallic conductor, which comprises coating the conductor with a rubber antioxidant consisting of about diphenyl-para-phenylene and about 65% phenyl alpha napthylamine extruding thereover a covering of a vulcanizable rubber insulating compound, and vulcanizing the vulcanizable compound.

6. The process of making a covered filamentary metallic conductor, which comprises coating the conductor with a solution of an antioxldantior rubber in an organic solvent, said antioxidant consisting of about 35% diphenyl-paraephenylone and about 65% phenyl-alpha-napthylamine, applying a covering of a vulcanizable rubber insulating compound thereover, and vulcanizing the covering, the degree of adhesion between the conductor and the vulcanized covering being controlled by the character of the solution employed to coat the article. I

7. The method of treating a filamentary metallic conductor, which comprises continuously ad.-

conductor a-film of a rubber antioxidant selected from the group consisting of butyraldehy'deaniline condensation product, diphenylamine acetone reaction product, phenyl-alpha nap- 5 thylamineand a mixture of about 35% diphenyling of butyraldehyde-aniline condensation prodvancing the conductor, applying to the advancing para-phenylene with about 65% phenyl-alphanapthyiamine, said coating material being in the liquid state, continuously extruding a vulcanizable rubber insulating compound upon the coated conductor, and continuously, vulcanizing the vulcanizable compound in situ.

8. An article of manufacture, which comprises a metallic article, a film on the article consisting of a rubber antioxidant selected from the group consisting of butyraldehyde-aniline condensation product, diphenylamine acetone reaction product, phenyl-alpha-napthylamine and a mixture of about 35% diphenyl-para-phenylene with about 65% phenyl-alpha-napthylamine, and a covering of rubber insulating compound vulcanized in situ over the film.

9. An article of manufacture, which comprises a filamentary metallic conductor, a film on the conductor consisting of a rubber antioxidant selected from the group consisting of butyraldehyde-aniline condensation product, diphenylamine acetone reaction product, pheny1-a1phanapthylamine and a mixture of about 35% diphenyl -para-phenylene with about 65% phenylalpha-napthylamine, and an insulating covering of rubber compound vulcanized over the film of antioxidant.

10. An article of manufacture, which comprises a filamentary metallic conductor, a film on the conductor consisting of a rubber antioxidant consisting of butyraidehyde-aniline condensation product, and an insulating covering of rubber compound vulcanized over the film of antioxidant.

11. An article of manufacture, which comprises a filamentary metallic conductor, afilm on the conductor consisting oi a rubber antioxidant consisting of phenyl-alpha-napthy1amine, and an insulating covering of rubber compound vulcanized over the film of antioxidant.

12. An article of manufacture, which comprises a filamentary metallic conductor, a film on the conductor consisting of a rubber antioxidant composed of about diphenyl-para-phenylene and about phenyl-alpha-napthylamine, and an insulating covering of rubber compound vulcanized over the film of antioxidant.

13. The process for insulating wires surfaced with metal of the group consisting of copp r and alloys thereof, which comprises coating such a wire with a rubber antioxidant selected from the group consisting of butyraldehyde-aniline condensation product, diphenylamine acetone reaction product, phenyl-alpha-napthylamine and a mixture of about 35% diphenyl-para-phenylene with about 65% phenyl-alpha-napthylamine, extruding thereover a covering of a vulcanizaole rubber insulating compound, and vulcanizing the vulcanizabie compound.

14. An article of manufacture, which comprises a wire surfaced with metal of the group consisting of copper and alloys thereof, a film on the wire consisting of a rubber antioxidant selected from the group consisting of butyraldehydeaniline condensation product, diphenylamine acetone reactlon product, phenyl-alpha-napthylamine and a mixture of about 35% diphenylpara-phenyiene with about 65% phenyl-alphanapthylamine, and an insulating covering of rubber compound vulcanized over the film of antioxidant.

THOMAS K. COX. 

